Unsable to load 'supervisor' panel

I have a HA installation running on a pi3b. I was having some issues programming a Sonoff device with the ESHome integration. After multiple tries to program the device, I decided to pull the plug on the pi for a reboot (yes, I know I shouldn’t just pull the plug) and somehow, I managed to screw up the HA installation.
Everything works except for the ‘Supervisor’ tab (can’t load page) and all of the integrations disappeared from the left side panel. I am assuming that the missing side panel entries are related to the supervisor panel not loading.
I am hoping that there is some setting or entry that I can reset to enable the Supervisor functions. I really don’t want to dump the entire HA installation and start from scratch.

Any help would be appreciated …

Doing some digging showed lots of instances of this but nothing I could use to fix my install.
I installed a new HA version on a new SD card and that is running fine but how to get the old configuration across …
I ran a backup via the HA pi command line interface and that completed ok. Alas, when I take the SD card across to my computer it sees it as unallocated space (yet it still boots in HA on the pi)
The computer I am using to look at the SD card is a Linux box and it sees the newly created HA data just fine. I am suspecting some corruption of the memory card but it is taunting me by running just fine on the pi (minus the supervisor panel)
I am at a loss as to how to get to the configuration backup.

I was able to make a configuration backup by hooking a monitor and keyboard to the HA pi and logging in to the command line interface. I then found the SD card to be corrupted and not recognized but with many an attempt, I finally got access long enough to download the backup. That was then transferred to the freshly prepared SD card, HA was started and the old configuration was restored.
Things are still not quite back to before but it’s getting very close and I am ever so happy that I did not need to configure everything from scratch.